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Taro L. Saito
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This document is a copy of http://code.google.com/p/snappy-java/
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---------------------------------------
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The snappy-java is a Java port of the snappy http://code.google.com/p/snappy/, a fast compresser/decompresser written in C++ developed by Google.
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== Features ==
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* [http://www.apache.org/licenses/LICENSE-2.0 Apache Licence Version 2.0]. Free for both commercial and non-commercial use.
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* Fast compression/decompression tailored to 64-bit CPU architecture.
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* JNI-based implementation to achieve comparable performance to the native C++ version.
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* Although snappy-java uses JNI, it can be used safely with multiple class loaders (e.g. Tomcat, etc.).
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* Portable across various operating systems; Snappy-java contains native libraries built for Window/Mac/Linux (32/64-bit). At runtime, snappy-java loads one of these libraries according to your machine environment (It looks system properties, `os.name` and `os.arch`).
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* Simple usage. Add the snappy-java-(version).jar file to your classpath. Then call compression/decompression methods in org.xerial.snappy.Snappy.
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== Performance ==
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* Snappy's main target is very high-speed compression/decompression with reasonable compression size. So the compression ratio of snappy-java is modest and about the same as `LZF` (ranging 20%-100% according to the dataset).
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* Here are some [https://github.com/ning/jvm-compressor-benchmark/wiki benchmark results], comparing snappy-java and the other compressors `LZO-java`/`LZF`/`QuickLZ`/`Gzip`/`Bzip2`. Thanks [http://twitter.com/#!/cowtowncoder Tatu Saloranta @cowtowncoder] for providing the benchmark suite.
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* The benchmark result indicates snappy-java is the fastest compreesor/decompressor in Java:
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* http://ning.github.com/jvm-compressor-benchmark/results/canterbury-roundtrip-2011-07-28/index.html
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* The decompression speed is twice as fast as the others:
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* http://ning.github.com/jvm-compressor-benchmark/results/canterbury-uncompress-2011-07-28/index.html
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== Download ==
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The current stable version 1.0.3.1 is available from here:
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* Release version: http://maven.xerial.org/repository/artifact/org/xerial/snappy/snappy-java
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* [Milestone] release plans
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* Snapshot version (the latest beta version): http://maven.xerial.org/repository/snapshot/org/xerial/snappy/snappy-java/
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If you are a Maven user, see [#Using_with_Maven]
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== Usage ==
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First, import `org.xerial.snapy.Snappy` in your Java code:
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{{{
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import org.xerial.snappy.Snappy;
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}}}
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Then use `Snappy.compress(byte[])` and `Snappy.uncompress(byte[])`:
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{{{
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String input = "Hello snappy-java! Snappy-java is a JNI-based wrapper of "
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+ "Snappy, a fast compresser/decompresser.";
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byte[] compressed = Snappy.compress(input.getBytes("UTF-8"));
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byte[] uncompressed = Snappy.uncompress(compressed);
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String result = new String(uncompressed, "UTF-8");
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System.out.println(result);
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}}}
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In addition, high-level methods (`Snappy.compress(String)`, `Snappy.compress(float[] ..)` etc. ) and low-level ones (e.g. `Snappy.rawCompress(.. )`, `Snappy.rawUncompress(..)`, etc.), which minimize memory copies, can be used. See also
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[http://code.google.com/p/snappy-java/source/browse/src/main/java/org/xerial/snappy/Snappy.java Snappy.java]
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===Stream-based API===
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Stream-based compressor/decompressor `SnappyOutputStream`/`SnappyInputStream` are also available for reading/writing large data sets.
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===Setting classpath==
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If you have snappy-java-(VERSION).jar in the current directory, use `-classpath` option as follows:
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{{{
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$ javac -classpath ".;snappy-java-(VERSION).jar" Sample.java # in Windows
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or
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$ javac -classpath ".:snappy-java-(VERSION).jar" Sample.java # in Mac or Linux
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}}}
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===Using with Maven===
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* Snappy-java is available from Maven's central repository: http://repo1.maven.org/maven2/org/xerial/snappy/snappy-java
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Add the following dependency to your pom.xml:
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{{{
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<dependency>
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<groupId>org.xerial.snappy</groupId>
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<artifactId>snappy-java</artifactId>
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<version>(version)</version>
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<type>jar</type>
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<scope>compile</scope>
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</dependency>
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}}}
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==Public discussion group==
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Post bug reports or feature request to the Issue Tracker: http://code.google.com/p/snappy-java/issues/list
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Public discussion forum is here: [http://groups.google.com/group/xerial?hl=en Xerial Public Discussion Group].
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== Building from the source code ==
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See the [http://code.google.com/p/snappy-java/source/browse/INSTALL installation instruction]. Building from the source code is an option when your OS platform and CPU architecture is not supported. To build snappy-java, you need Mercurial(hg), JDK (1.6 or higher), Maven (3.x or higher is required), g++ compiler (mingw in Windows) etc.
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{{{
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$ hg clone https://snappy-java.googlecode.com/hg/ snappy-java
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$ cd snappy-java
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$ make
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}}}
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A file `target/snappy-java-$(version).jar` is the product additionally containing the native library built for your platform.
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==Miscellaneous Notes==
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===Using snappy-java with Tomcat 6 (or higher) Web Server===
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Simply put the snappy-java's jar to WEB-INF/lib folder of your web application. Usual JNI-library specific problem no longer exists since snappy-java version 1.0.3 or higher can be loaded by multiple class loaders in the same JVM by using native code injection to the parent class loader (Issue 21).
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----
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Snappy-java is developed by [http://www.xerial.org/leo Taro L. Saito]. Twitter [http://twitter.com/#!/taroleo @taroleo]
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The snappy-java is a Java port of the snappy
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<http://code.google.com/p/snappy/>, a fast C++ compresser/decompresser developed by Google.
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## Features
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* [Apache License Version 2.0](http://www.apache.org/licenses/LICENSE-2.0). Free for both commercial and non-commercial use.
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* Fast compression/decompression tailored to 64-bit CPU architecture.
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* JNI-based implementation to achieve comparable performance to the native C++ version.
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* Although snappy-java uses JNI, it can be used safely with multiple class loaders (e.g. Tomcat, etc.).
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* Portable across various operating systems; Snappy-java contains native libraries built for Window/Mac/Linux (32/64-bit). At runtime, snappy-java loads one of these libraries according to your machine environment (It looks system properties, `os.name` and `os.arch`).
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* Simple usage. Add the snappy-java-(version).jar file to your classpath. Then call compression/decompression methods in org.xerial.snappy.Snappy.
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## Performance
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* Snappy's main target is very high-speed compression/decompression with reasonable compression size. So the compression ratio of snappy-java is modest and about the same as `LZF` (ranging 20%-100% according to the dataset).
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* Here are some [benchmark
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results](https://github.com/ning/jvm-compressor-benchmark/wiki), comparing
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snappy-java and the other compressors
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`LZO-java`/`LZF`/`QuickLZ`/`Gzip`/`Bzip2`. Thanks [Tatu Saloranta @cotowncoder](http://twitter.com/#!/cowtowncoder) for providing the benchmark suite.
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* The benchmark result indicates snappy-java is the fastest compreesor/decompressor in Java:
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* <http://ning.github.com/jvm-compressor-benchmark/results/canterbury-roundtrip-2011-07-28/index.html>
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* The decompression speed is twice as fast as the others:
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* <http://ning.github.com/jvm-compressor-benchmark/results/canterbury-uncompress-2011-07-28/index.html>
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## Download
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The current stable version 1.0.3.1 is available from here:
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* Release version: http://maven.xerial.org/repository/artifact/org/xerial/snappy/snappy-java
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* [Milestone] release plans
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* Snapshot version (the latest beta version): http://maven.xerial.org/repository/snapshot/org/xerial/snappy/snappy-java/
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If you are a Maven user, see [#Using_with_Maven]
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## Usage
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First, import `org.xerial.snapy.Snappy` in your Java code:
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import org.xerial.snappy.Snappy;
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Then use `Snappy.compress(byte[])` and `Snappy.uncompress(byte[])`:
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String input = "Hello snappy-java! Snappy-java is a JNI-based wrapper of "
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+ "Snappy, a fast compresser/decompresser.";
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byte[] compressed = Snappy.compress(input.getBytes("UTF-8"));
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byte[] uncompressed = Snappy.uncompress(compressed);
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String result = new String(uncompressed, "UTF-8");
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System.out.println(result);
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In addition, high-level methods (`Snappy.compress(String)`, `Snappy.compress(float[] ..)` etc. ) and low-level ones (e.g. `Snappy.rawCompress(.. )`, `Snappy.rawUncompress(..)`, etc.), which minimize memory copies, can be used. See also
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[http://code.google.com/p/snappy-java/source/browse/src/main/java/org/xerial/snappy/Snappy.java Snappy.java]
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### Stream-based API
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Stream-based compressor/decompressor `SnappyOutputStream`/`SnappyInputStream` are also available for reading/writing large data sets.
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### Setting classpath
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If you have snappy-java-(VERSION).jar in the current directory, use `-classpath` option as follows:
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$ javac -classpath ".;snappy-java-(VERSION).jar" Sample.java # in Windows
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or
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$ javac -classpath ".:snappy-java-(VERSION).jar" Sample.java # in Mac or Linux
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### Using with Maven
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* Snappy-java is available from Maven's central repository: http://repo1.maven.org/maven2/org/xerial/snappy/snappy-java
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Add the following dependency to your pom.xml:
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<dependency>
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<groupId>org.xerial.snappy</groupId>
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<artifactId>snappy-java</artifactId>
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<version>(version)</version>
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<type>jar</type>
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<scope>compile</scope>
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</dependency>
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## Public discussion group
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Post bug reports or feature request to the Issue Tracker: <http://code.google.com/p/snappy-java/issues/list>
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Public discussion forum is here: <http://groups.google.com/group/xerial?hl=en Xerial Public Discussion Group>
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## Building from the source code
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See the [http://code.google.com/p/snappy-java/source/browse/INSTALL installation instruction]. Building from the source code is an option when your OS platform and CPU architecture is not supported. To build snappy-java, you need Mercurial(hg), JDK (1.6 or higher), Maven (3.x or higher is required), g++ compiler (mingw in Windows) etc.
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$ git clone https://github.com/xerial/snappy-java.git
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$ cd snappy-java
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$ make
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A file `target/snappy-java-$(version).jar` is the product additionally containing the native library built for your platform.
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## Miscellaneous Notes
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### Using snappy-java with Tomcat 6 (or higher) Web Server
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Simply put the snappy-java's jar to WEB-INF/lib folder of your web application. Usual JNI-library specific problem no longer exists since snappy-java version 1.0.3 or higher can be loaded by multiple class loaders in the same JVM by using native code injection to the parent class loader (Issue 21).
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----
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Snappy-java is developed by [Taro L. Saito](http://www.xerial.org/leo). Twitter [@taroleo](http://twitter.com/#!/taroleo)
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